Heating panel



April 1966 c. R. THORPE, JR I 3,244,858

HEATING PANEL Filed Nov. 8, 1963 3 Sheets-Sheet l INVENTOR ATTORNEY Charles R. Thorpe, Jr.

April 5, 1966 c. R. THORPE, JR 3,244,358

HEATING PANEL Filed Nov. 8, 1963 r 3 Sheets-Sheet 2 INVENTOR Charles R. Thorpe, Jr.

ATTORNEY April 5, 1966 c. R. THORPE, JR

HEATING PANEL 3 Sheets-Sheet 5 Filed Nov. 8, 1963 INVENTOR Charles R. Thorpe, Jr.

ATTORNEY United States Patent O M 3,244,858 HEATHNG PANEL Charles R. Thorpe, (in, Avonlake, Ohio, assignor to American Radiator & Standard Sanitary Corporation, New York, N.Y., a corporation of Delaware Fiied Nov. 8, 1963, Ser. No. 322,474 1 Claim. (Cl. 2193 i5) This invention relates to an improved electric heating panel for use in various heating and drying applications. The panel may be used, for example, as a towel and clothing dryer, a plate and serving dish warmer, for providing supplemental heat for human comfort or for animal comfort, for dehumidifying closed spaces, and for warming of automobile crankcases for cold weather starts.

The panel of the present invention is constructed to afford uniform heating and because of its practical dimensions and weight may be used for a wide variety of heating and drying applications. The panel is rugged and its performance is unimpaired by moisture or high humidity. The design is such that it may be placed directly in contact with the object being heated or dried without any danger that such objects will be overheated, scorched, or in any other way adversely effected by the contact of the panel with such objects. The panel may be affixed to various structures to facilitate its use for heating and drying. For example, it may be safely hung from a towel rack or suspended under an automobile crankcase. The panel may safely be placed on furniture such as a table for use as a plate and serving dish warmer or it may be used on the floor of the home as a means for drying wet shoes, or as a foot warmer, or in an animal enclosure for keeping pets warm.

Accordingly, an object of the present invention is to provide a simple and effective heating and drying panel which is adapted for a wide variety of uses, which may be used in absolute safety without danger of undue heating and without any danger of burning and scorching, which is rugged and moisture resistant, and which may be manufactured at relatively low cost.

With the above and other objects in view, which will appear more fully from the following detailed description, the invention consists of a heating element wound in gradient fashion about a generally fiat piece of core material. Suitable insulation is provided about the heating element and the entire unit is encased in a casing which may have means adapting it to be suspended from or attached to various structures to provide heating and drying of adjacent objects. An insulated cord leads from the panel so that it may be plugged into a conventional electrical outlet. A thermostat and electric switch may be provided in the panel if desired.

Other objects and features of the invention will appear as the description of the particular physical embodiment selected to illustrate the invention progresses.

For a better understanding of the present invention reference should be had to the accompanying drawings wherein like numerals of reference indicate similar parts throughout the several views and wherein:

FIG. 1 is a perspective view of a heating panel constructed according to the invention.

FIGS. 2 through 6 are perspective views showing practical applications of the heating panel.

FIG. 7 is a plan view of the heating panel of FIG. 1.

FIG. 8 is a side view, partly broken away, looking along line 8-8 in FIG. 7.

FIG. 9 is a sectional view taken along the line 99 of FIG. 7.

FIG. 10 is a partial plan view of an alternate construction with the outer casing removed.

3,244,858 Patented Apr. 5, 1966 Before explaining the present invention in detail it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed is for the purpose of description and no of limitation.

The heating panel 10 shown in FIG. 1 is of a generally fiat construction having an electric cord 12 leading therefrom and adapted to be received in a conventional electrical outlet. Openings or eyelets such as at 14 may be provided to facilitate suspending the heating panel from various structures. For example, the panel may be suspended from a towel rack 16 by means of plastic or wire hooks 18 for drying an article of clothing 20 draped over the panel. The openings 14 may also be used to facilitate attaching the panel adjacent an automobile crankcase 22 (FIG. 2) by use of plastic or wire hooks 24 or other suitable attaching means. Other uses of the panel are shown in FIGS. 4 to 6. In FIG. 4, the panel is shown supported on a stand 17 in order that it may be used for dehumidifying a closed space. In FIG. 5, the panel is shown being used as a warming tray while in FIG. 6, it is being used to provide supplemental heat for human comfort.

The panel 10 may be provided with a thermostat 26 for temperature control, cycling the power on and off during confined or over voltage conditions. An electrical switch 28 may also be provided for turning the unit on and off, for selecting high or low heat, or for providing both of these functions.

The details of construction of the panel are shown in FIGS. 7 to 9 wherein there is shown a generally flat core 30 which may be made of asbestos and about which heating element wire 32, such as nickel-chrome, is wound alternately about the front and back of the core in gradient fashion to avoid overheating of any particular area of the panel. Slots such as at 34 are provided along longitudinal edges of the core 30 to locate and hold in place the heating element wire 32 in the proper position about the core and also to prevent the heated wire 32 from overheating the edges of the panel. As shown in FIG. 7, a conductor 36 extends from the cord 12 to the thermostat 26 and from there a conductor 38 extends to the switch 28. From the switch 28, the pair of heating wire elements 32 are wound around the cord within the slots 34 and are led back to the cord 12 as shown at M and 41. The core 39 is provided with cutouts to receive the switch 23, the thermostat 26, and a further cutout 42 is provided to receive the end of the cord 12, the end of the latter being supported on the panel by an outer casing to be hereinafter described. The ends of the heating element portions 4-0 and 41 may have turns taken about the cutout 42 and the adjacent slot as shown at 44 to aid in securing the heating wire element in place.

After the wire has been wound about the core, means may be provided for temporarily securing the wire into place such as by applying tape, described later with reference to the embodiment of FIG. 10. A relatively thin sheet of dielectric material 48 such as a glassmat is then placed over the heating element. A sheet of insulating material such as asbestos 50 is then placed adjacent the dielectric 48 and the entire assembly is then encased within a metal casing 52. The glass mat may consist of an overlapping network of glass flakes which provides both mechanical reinforcement and a continous dielectric barrier. As an example, the mat may be composed of percent fiber glass and 15 percent cellulose binder. When using asbestos at 50, if desired, a sealer such as 133 F.

3,244.,ses

Irvington class F. varnish may be used to impregnate and coat the asbestos. One or both sides of the dielectric 48 may also be varnished. For example, varnish may be placed on the side of the glass mat toward the outer casing so that the varnish is protected by the glass mat from complete polymerization and browning.

The casing 52 for the panel may be made, for example, of sheet steel or aluminum which is doubled over on itself along peripheral edge portions such as shown at 54 (FIG. 9). The overlapping portion 54 may be made by bending an extended peripheral edge of the lower plate 53 of the casing 52 over and around the peripheral edge of the assembly to mate with a cooperatingperipheral edge on the upper plate 55 as clearly shown in FIG. 9 at 54. The peripheral edges are sealed by the use of either a rubber or silicone adhesive or seal to prevent moisture and water from entering the casing.

Openings 14 may be provided by adjacent mating and overlapping cylindrical sections 56 as shown in FIG. 9. Reinforcing members such as grommets (not shown)may be provided in the openings 14 if desired.

The casing 52 is provided with embossings 59, 61 and 63 integral therewith to enclose respectively the switch 28, the thermostat 26, and the end of the cord 12 therewithin and thereby provide a watertight seal. The end of the cord 12 is provided with a rubber bushing 58 which is secured and sealed between the embossed sections 63 of the panel as best shown in FIGS. 7 and8. The switch 28 and thermostat 2'6'may be of a conventional design and therefore do not of themselves form a part of this invention. The switch, for example, may be'a General Electric Rotary switch, Series 300 and the thermostat may be the Franklin Dales Co. model DA4L. A portion of the switch 28 extends through an opening in one side of the casing 52 to receive an operating handle 67. The switch 28 and thermostat 26 need not be provided, particularly for panels of low wattage.

In the alternate embodiment of FIG. 10, for example, there is no switch although there is a cutout 60 for it in the core 30. In this last mentioned embodiment of FIG. 10, in which the outer casing is shown removed, a single heating element wire 70 is wound about the core instead of the double wire as in the first embodiment. Also tapes 72 are shown for temporarily securing the heating element wires to the core 30 before the other layers of material are placed thereon. This latter figure also clearly shows the bushing 58 on the end of the cord 12.

When the outer casing 52 is made of sheet steel it may be coated with an enamel steel surface which has been found to be a better emitter of heat than a shiny steel plate. The coating may be a heat-resistant enamel. Patterned aluminum sheets may also be used for the casing. This affords a pleasing appearance and provides good heat transfer without requiring painting. Also when using aluminum, a fiat, coated, embossed, or anodized surface may be used.

Thepanel may be constructed as a rectangle with the openings 14 provided in at least three corners to allow the panel to be hung with itsnarrower or longer edge up, thereby adapting it to be accommodated in various size towel racks, for example. The panel may be constructed of a convenient size for the intended purpose, The panel may be designed so that it will operate at a temperature below 200 F. in order to insure human comfort.

From the above description it will be evident that the panel of the present invention is of a rugged and relatively inexpensive construction. It is resistant to adverse effects by moisture. The panel may be placed directly in contact with objects being heated or dried without any danger that such objects will be overheated or scorched. The panel may be affixed to various structures to facilitate its use for heating and drying. It may be. used with absolute safety with no danger of adversely affecting the objects which it contacts.

The invention hereinabove described may be varied. in construction within the scope of the claim, for the particular device selected to illustrate the invention is but one of many possible embodiments of the same. The invention, therefore, is not to be restricted to the precise detail of the structure shown and described.

What is claimed is:

An electric heating panel comprising a fiat dielectric core; wire-type resistance heating means wound about the core; compressible dielectric sheet means positioned against opposite faces of the fiat core; a casing comprising two spaced parallel metal plates positioned against the outer faces of respective ones of the dielectric sheet means; one of said metal plates having a peripheral rim wall extending toward the other metal plate and secured thereto about the plate periphery; said rim wall having an opening therethrough; current supply means for the resistance heating means, comprising an insulated electric cord having a strain-release bushing carried thereon, said bushing being anchored in the rim wall opening to prevent displacement of the cord; said fiat dielectric core having a cut-out in its edge, said cut-out registering with the bushing and providing a free space adjacent thereto; the wire type resistance heating means including lead wires having direct connection with the electric cord wiring in the cut-out free space; said dielectric core having an opening theret-hrough adjacent the cut-out; a thermostatically-operated switch disposed in said opening; the lead wires for the resistance heating means having electric connections with the switch, whereby said switch controls current flow through the heating means; the compressible dielectric sheet means having face portions thereof overlying and physically engaging the switch to cushionably position same Within the panel.

References Cited by. the Examiner UNITED STATES PATENTS 1,401,186 12/1921 Prenzlow 33830l 2,460,625 2/ 1949 Ellis 219-342 2,623,150 12/1952 Boecher et al 219213 3,041,441 6/1962 Elbert et al 21 9345 3,160,736 12/1964 Catherson 219-345 X FOREIGN PATENTS 127,496 6/ 1919 Great Britain. 286,807 3/ 1928 Great Britain.

ANTHONY BARTIS, Acting Primary Examiner, RICHARD M. WOOD, Examiner. C. L. ALBRITTON, Assistant Examiner, 

